000
FXUS64 KBRO 310013
AFDBRO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
713 PM CDT THU JUL 30 2015
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...
EXPECT VFR CONDITIONS TO PREVAIL THROUGH THE EVENING AND
OVERNIGHT HOURS. EXPECT AGAIN SOME LOW CLOUD DECKS OR FOG IN THE
MORNING HOURS. WILL CONTINUE TO MAINTAIN MVFR/IFR CONDITIONS FOR
THE RGV AIRPORTS DURING THE EARLY MORNING HOURS WITH VFR
CONDITIONS RETURNING ONCE AGAIN AFTER SUNRISE TOMORROW. OTHERWISE
EXPECT VFR CONDITIONS ON FRIDAY.
&&
.PREV DISCUSSION... /ISSUED 257 PM CDT THU JUL 30 2015/
SHORT TERM /NOW THROUGH FRIDAY NIGHT/...VSBL SATL AND KBRO RADAR
IMAGERY SHOWS AREAS OF CONV FIRING OFF OVER NORTHEAST MEXICO WHERE
SOME BETTER INSTABILITY IS INTERACTING WITH THE DAYTIME HEATING. THE
OVERALL MOTION OF THIS CONV IS GENERALLY TO THE W-NW WHICH IS IN
LINE WITH THE LOW AND MID LEVEL WIND FLOW. THIS WILL KEEP THIS CONV
FROM MOVING INTO DEEP SOUTH TX THIS EVENING. ON FRIDAY DEEPER LAYER
MOISTURE POOLED OVER THE NORTHERN GULF OF MEX WILL START TO DRIFT
WEST TOWARDS THE LOWER TX COASTLINE. IN ADDITION SOME BROAD 500 MB
TROFFING OVER THE GULF WILL START TO EDGE WEST TOWARDS THE
COASTLINE. THIS WILL COMBINE TO ALLOW FOR A BIT OF AN INCREASE IN
THE CONV POTENTIAL TOMORROW ESPECIALLY OVER THE MARINE LOCATIONS AND
ALONG THE LOWER TX COASTLINE. THE ECMWF IS THE DRIEST OF THE MODELS
WHILE THE MET COMES IN WITH SOME NEAR 20% POPS FOR TOMORROW. SO WILL
OPT FOR THE SLIGHTLY WETTER MET NUMBERS. SINCE THE MAV AND MET
GUIDANCE IS TRYING TO ADVECT IN A BIT MORE MOISTURE OVER THE REGION
THE FORECAST TEMPS GENERATED BY THESE TWO MODEL SETS ARE A BIT
COOLER VERSUS THE DRY ECMWF NUMBERS. SO WILL GO WITH A BLEND OF THE
SLIGHTLY LOWER MAV AND MET TEMPS THROUGH TOMORROW NIGHT.
THE GFS AND NAM GUIDANCE ARE ALSO HINTING AT SOME POTENTIAL FOR
PATCHY FOG LATE TONIGHT THROUGH SUNRISE FRIDAY. SINCE WE HAD THIS
OCCUR THIS MORNING WILL GO AHEAD AND MENTION THIS FOR TOMORROW
MORNING MAINLY DUE TO THE LIGHTER SURFACE WIND REGIME.
LONG TERM /SATURDAY THROUGH THURSDAY/...DEEP LAYER MOISTURE WILL
INCREASE ACROSS THE WESTERN GULF OF MEXICO SATURDAY INTO SUNDAY AS A
WEAK 500MB LOW/INVERTED TROUGH ACROSS THE WESTERN GULF OF MEXICO
MOVES WESTWARD. THIS MID LEVEL FEATURE ALONG WITH AN INCREASE IN
MOISTURE AND DAYTIME HEATING WILL SUPPORT A SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS OVER THE AREA ON SATURDAY. THIS MID LEVEL SYSTEM
OVER THE GULF OF MEXICO IS EXPECTED TO WEAKEN AS IT MOVES INLAND
OVER EASTERN MEXICO LATE IN THE WEEKEND. ISOLATED TO SCATTERED
CONVECTION IS POSSIBLE ACROSS THE LOWER TEXAS COASTAL WATERS
SATURDAY NIGHT INTO SUNDAY DUE TO SOME LINGERING MOISTURE. HOT AND
DRY CONDITIONS RETURN TO DEEP SOUTH TEXAS BY EARLY NEXT WEEK AND
CONTINUE THROUGH THE REST OF THE FORECAST PERIOD AS THE 500 MB RIDGE
BUILDS OVER THE REGION.
MARINE...NOW THROUGH FRIDAY NIGHT...THE WEAK PGF WILL ALLOW FOR
FAIRLY LIGHT MARINE WINDS AND LOW SEAS TO PREVAIL THROUGHOUT THE
SHORT TERM PERIOD. NO SCEC OR SCA CONDITIONS EXPECTED THROUGH FRI
NIGHT.
SATURDAY THROUGH TUESDAY...LIGHT AND VARIABLE WINDS WILL PREVAIL
ACROSS THE COASTAL WATERS SATURDAY AND SATURDAY NIGHT AS WEAK LOW
PRESSURE CONTINUES ACROSS THE NORTH CENTRAL GULF OF MEXICO. LIGHT TO
OCCASIONALLY MODERATE SOUTHERLY WINDS ARE EXPECTED ACROSS THE LOWER
TEXAS COAST SUNDAY INTO EARLY NEXT WEEK AS THE PRESSURE GRADIENT
REMAINS FAIRLY WEAK ACROSS THE WESTERN GULF.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
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HTTP://WEATHER.GOV/RGV